As demands for higher currents & higher voltages keep increasing, the Electrical and Thermal isolation between Power components and the rest of the circuitry pose a great challenge in modern PMIC designs.
Conventional bipolar-double diffused metal oxide—complementary metal oxide (BCD) manufacturing processes use heavily doped buried regions, subsequent silicon epitaxial growth and heavily doped sinker implants & diffusions for contacting the buried regions from the top. Other processes are using silicon on insulator (SOI) wafers to get the required isolation, however both options are quite expensive and increase the process complexity.